We explored the bonding properties of the quantum corral (a circle of 48 iron atoms placed on a copper surface) reported by Crommie et al. in 1993, along with variants, as an artificial atom using an atomic force microscope (AFM). The original corral geometry confines 102 electrons to 28 discrete energy states, and we found that these states can form a bond to the front atom of the AFM with an energy of about 5 millielectron volts. The measured forces are about 1/1000 of typical forces in atomically resolved AFM. The confined electrons showed covalent attraction to metal tips and Pauli repulsion to CO-terminated tips. The repulsion at close distance was evident from the response of corral states created by deliberately placing single iron atoms inside the corral. The forces scaled appropriately with a 24-atom corral.

我们探索了 Crommie等人报道的量子围栏（放置在铜表面上的 48 个铁原子的圆圈）的键合特性。1993 年，连同变体，作为使用原子力显微镜 (AFM) 的人造原子。原始的畜栏几何结构将 102 个电子限制在 28 个离散的能态中，我们发现这些能态可以以大约 5 毫电子伏特的能量与 AFM 的前原子形成键。测得的力约为原子分辨 AFM 中典型力的 1/1000。受限电子显示出对金属尖端的共价吸引力和对 CO 终止尖端的泡利排斥。从通过故意将单个铁原子放置在畜栏内所产生的畜栏状态的响应中可以明显看出近距离的排斥。这些力量以 24 个原子的畜栏适当地缩放。